textproduct: Albany

WHAT HAS CHANGED

Increased PoPs and QPF across far southeastern Litchfield County tomorrow, but with a very sharp QPF gradient it remains uncertain how far north and west these higher amounts will extend. Also bumped up winds/gusts Sunday and Monday.

KEY MESSAGES

1) Periods of rain expected late tonight into Friday night for portions of southwestern New England and the Mid Hudson Valley. Any rain will be beneficial with no flooding concerns.

2) More widespread showers expected Saturday and Saturday night. Drier and cooler conditions are then expected for the first half of next week.

DISCUSSION

KEY MESSAGE 1...As of 12:45 AM EST...Current sfc analysis shows that the cold front that brought showers yesterday is located just west of the Capital District. The best upper forcing remains off to our west, but persistent weak low-level convergence along the front within a moist airmass is leading to a few isolated showers in the vicinity and ahead of the cold front. Behind the front, current satellite imagery shows some partial clearing, and given the low-level moisture from yesterday's showers we should see patchy fog develop, especially in the more sheltered areas where winds become calm. Otherwise, the rest of the night will be unseasonably warm and muggy with lows in the mid 40s to upper 50s.

Late tonight/early tomorrow morning, increasingly diffluent flow aloft will lead to an uptick in shower activity along the front as it slowly makes its way into western New England. Then, by tomorrow afternoon, a southern stream shortwave rounding the base of an upper- level low (ULL) centered over the southern Great Lakes will induce sfc cyclogenesis off the east coasts, with a wave of low pressure developing along the stalled frontal boundary. Forcing looks impressive, with CVA, the right entrance of the upper jet nearby, and increased low-level convergence near the front. The impressive forcing will overlap with deep Atlantic moisture (PWATs to 1.5-1.75") ahead of the front. With some pockets of elevated instability, a period of steady moderate to locally heavy rain is expected across portions of southern New England tomorrow afternoon. The big question is how far west the front stalls, and thus how far west the precip shield makes it into our region. There will also be a very sharp accumulation gradient on the northwestern side of the rain shield as well. Currently, southeastern Litchfield County near Rte 6 has a 50% chance to see >1" of rain according to the latest NBM, but these probabilities drop to <20% northwest of Rte 202. Our current deterministic forecast has some additional light rain reaching southeastern Dutchess and Berkshire Counties, with most of the rest of the region remaining mainly dry but cloudy tomorrow. Even if rainfall amounts end up above the current forecast, the very dry antecedent conditions should prevent any flooding concerns. Tomorrow will again be on the warm side with highs well into the 60s.

KEY MESSAGE 2...Rain associated with this coastal low comes to an end Friday night. However, the parent ULL will be slowly drifting overhead Saturday into Saturday night. Its exact track remains somewhat uncertain, but general consensus still seems to be near or just north of the I-90 corridor. With moisture wrapping back around the ULL, fairly widespread showers overspread the region from west to east Saturday, lasting into Saturday night. An inverted trough at the sfc extending from the deepening coastal low back towards the ULL will result in increased low-level convergence, helping to locally enhance coverage and intensity of showers. Latest 00z guidance has ticked slightly north with this feature keeping it mainly north of I-90. Most areas will see at least an additional quarter to half inch of rain, with higher amounts of 0.5 to 1 inch possible where the inverted trough sets up. Lower rainfall amounts closer to a tenth of an inch expected closer to I-84, especially if north trend with the inverted trough continues. Most areas dry out Sunday morning, but some lingering precip will be possible in the high terrain north of I-90 as the upper deformation axis passes just north of our region with some W/NW upslope enhancement also expected.

As the system pulls away from our region, it cooler and less humid air will be advected into our region with W/NW winds becoming breezy (gusts 25-35 mph Sunday and Monday). Generally drier conditions are then expected for at least the first half of next week, although a few moisture-starved upper disturbances embedded in NW flow aloft may lead to some light showers for northern/high terrain areas Monday and again Tuesday night/early Wednesday. Temperatures generally remain near normal (highs in the 40s to 50s and lows in the 20s to 30s) across the region for the first half of the week, but deeper upper troughing over the eastern part of the country may lead to temperatures trending below normal by the end of next week.

AVIATION /06Z FRIDAY THROUGH TUESDAY/

Along with lingering low level moisture, enough clearing of the clouds has occurred to allow for the development of radiational fog at KGFL. Through the rest of the overnight hours, IFR/LIFR radiational fog is expected there through daybreak. Some MVFR mist may linger an hour or two after sunrise, but improvement should occur. Meanwhile, IFR low stratus clouds have been hanging around KALB for the past few hours. This may hang on a little bit longer, but satellite trends suggest these should move out. Once that occurs, some IFR radiational fog is expected for KALB through daybreak as well, with visibility as low as 1-2SM there. Meanwhile, satellite trends suggest some MVFR stratus will likely continue at KPOU and KPSF through the rest of the overnight hours. There probably won't be enough clearing for radiational fog to impact those sites, but MVFR cigs will continue through the rest of the overnight hours. For all sites, winds will be fairly light to calm through sunrise.

A period of showers is expected to impact KPSF/KPOU during the mid to late morning hours. This activity should mainly stay southeast of KGFL, but could briefly clip KALB, so will include a PROB30 there. Within showers, MVFR conditions are expected, but brief reductions to IFR for visibility can't be ruled out at KPSF/KPOU. Surface winds will continue to be light.

Behind these showers, flying conditions should return to VFR by late in the day for all sites. BKN-OVC cigs at 6-10 kft will be in place for all sites for the late day and into Friday night. With the clouds around, this should help prevent widespread radiational fog, but will need to monitor satellite trends in case any clearing does develop, as that could allow some fog to form. Winds on Friday night look to be light to calm for all sites.

Outlook...

Saturday Night: High Operational Impact. Breezy. Definite RA. Sunday: Low Operational Impact. Breezy. Slight Chance of RA. Sunday Night: Low Operational Impact. Slight Chance of RA. Monday: Moderate Operational Impact. Windy With Gusts To 30 kts. NO SIG WX. Monday Night: No Operational Impact. NO SIG WX. Tuesday: No Operational Impact. NO SIG WX. Tuesday Night: No Operational Impact. NO SIG WX. Veterans Day: No Operational Impact. NO SIG WX.

ALY WATCHES/WARNINGS/ADVISORIES

CT...None. NY...None. MA...None. VT...None.